The neurointermediate lobe of the toad, Xenopus laevis, synthesizes and releases melanocyte stimulating hormone (MSH). Lobes from dark adapted toads synthesize tenfold more protein and peptide (MSH) than light adapted toads. The release of MSH appears to be under the regulation of dopamine from the median eminence. Synthesis of beta-MSH (and possibly the opiate peptide, endorphin) from a protein precursor in the intermediate lobe is actively under study.